Deciphering the molecular landscape of microcephaly in 87 Indian families by exome sequencing

Microcephaly is a frequent feature of neurodevelopmental disorders (NDDs). Our study presents the heterogeneous spectrum of genetic disorders in patients with microcephaly either in isolated form or in association with other neurological and extra-neural abnormalities. We present data of 91 patients from 87 unrelated families referred to our clinic during 2016–2020 and provide a comprehensive clinical and genetic landscape in the studied cohort. Molecular diagnosis using exome sequencing was made in 45 families giving a yield of 51.7%. In 9 additional families probable causative variants were detected. We identified disease causing variations in 49 genes that are involved in different functional pathways Among these, 36 had an autosomal recessive pattern, 8 had an autosomal dominant pattern (all inherited de novo), and 5 had an X-linked pattern. In 41 probands where sequence variations in autosomal recessive genes were identified 31 were homozygotes (including 16 from non-consanguineous families). The study added 28 novel pathogenic/likely pathogenic variations. The study also calls attention to phenotypic variability and expansion in spectrum as well as uncovers genes where microcephaly is not reported previously or is a rare finding. We here report phenotypes associated with the genes for ultra-rare NDDs with microcephaly namely ATRIP, MINPP1, PNPLA8, AIMP2, ANKLE2, NCAPD2 and TRIT1.     

Genomic and phenotypic delineation of congenital microcephaly

PurposeCongenital microcephaly (CM) is an important birth defect with long term neurological sequelae. We aimed to perform detailed phenotypic and genomic analysis of patients with Mendelian forms of CM.MethodsClinical phenotyping, targeted or exome sequencing, and autozygome analysis.ResultsWe describe 150 patients (104 families) with 56 Mendelian forms of CM. Our data show little overlap with the genetic causes of postnatal microcephaly. We also show that a broad definition of primary microcephaly —as an autosomal recessive form of nonsyndromic CM with severe postnatal deceleration of occipitofrontal circumference—is highly sensitive but has a limited specificity. In addition, we expand the overlap between primary microcephaly and microcephalic primordial dwarfism both clinically (short stature in >52% of patients with primary microcephaly) and molecularly (e.g., we report the first instance of CEP135-related microcephalic primordial dwarfism). We expand the allelic and locus heterogeneity of CM by reporting 37 novel likely disease-causing variants in 27 disease genes, confirming the candidacy of ANKLE2, YARS, FRMD4A, and THG1L, and proposing the candidacy of BPTF, MAP1B, CCNH, and PPFIBP1.ConclusionOur study refines the phenotype of CM, expands its genetics heterogeneity, and informs the workup of children born with this developmental brain defect.     

Methanol-induced monoamine changes in hypothalamus and striatum of albino rats

This paper suggests that like ethanol, methanol also produces certain changes in the steady state level of monoamines in hypothalamus and striatum of albino rats. Though, the toxic manifestations of methanol are attributed to the metabolic end product of methanol viz. formic acid by several workers, we report here that the methanol-induced brain monoamine changes, at least, could be attributed to the direct action of methanol rather than to its metabolic end products like formaldehyde or formate. Studies in the steady state level of rat brain monoamines have shown that after methanol administration (3 g/kg), there is severe depletion of dopamine level in striatum but a significant increase in the level of dopamine, serotonin and 5-hydroxy indole acetic acid in hypothalamus. At the same time, norepinephrine and epinephrine levels are reduced in hypothalamus as well as in striatum. These effects do not seem to be induced by metabolic acidosis. The changes in monoamine levels are very well correlated with the blood and brain level of methanol as evidenced by maintaining a higher methanol level either by simultaneous administration of ethanol or by blocking methanol metabolism by pretreatment with 4-methyl pyrazole and 3-amino-1,2,4-triazole. It is thus postulated that monoamine changes induced by methanol appear to be the direct effect of methanol per se on the monoaminergic neuronal membranes.     

Diagnostic significance of estimation of serum apolipoprotein A along with alpha-fetoprotein in alcoholic cirrhosis and hepatocellular carcinoma patients

The serum apolipoprotein A (Apo A) and alpha-fetoprotein (AFP) were evaluated in histologically verified 30 cases of alcoholic cirrhosis and 18 cases of hepatocellular carcinoma (HCC). The latter were also divided into subgroups depending on the presence or absence of associated cirrhosis. Serum Apo A levels were found to be significantly decreased in cirrhotics (p less than 0.001) compared to controls and non-cirrhotic HCC patients. In 22 cases of alcoholic cirrhosis (AFP less than 10 ng/ml) and 12 cases of HCC (AFP greater than 600 ng/ml), the AFP levels itself were diagnostic, but in the remaining cases, AFP levels (100-600 ng/ml) were not able to differentiate between cirrhosis and malignancy. In this later group of patients with low pathological range of AFP, serum Apo A levels found to be significantly decreased in alcoholic cirrhotic patients (p less than 0.001) compared to HCC patients. Thus, estimation of Apo A levels may be helpful to interpret the AFP values at lower pathological range due to suspected liver pathology.     

Urinary levels of taurine in mentally retarded children

ABSTRACT. Urinary taurine levels were estimated in 29 mentally retarded children. These levels were then compared with those of normal healthy children. The urinary taurine levels were significantly higher in the mentally retarded subjects. There is probably an intriguing relationship between taurine levels and mental retardation.     

FNAC diagnosis of tuberculosis--an eight years study at Mangalore

1. FNAC is a very useful adjunct in the diagnosis of tuberculosis: 2. Diagnosis of tuberculosis can be made by the demonstration of epithelioid granulomas with or without caseation even in the absence of AFB. 3. Necrotic features whether acellular or accompanied by neutrophilic infiltrate are usually misdiagnosed as suppurative abscesses. Such smears however show high AFB positivity and thus the diagnosis of tuberculosis is still possible even in the absence of epithelioid granulomas. 4. Therefore all smears obtained by FNAC of suspected tuberculous lesions should be subjected to ZN staining for AFB.